Photoluminescence Quenching in Single-Layer MoS2 via Oxygen Plasma Treatment

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• 作者：Narae Kang ; Hari P. Paudel ; Michael N. Leuenberger ; Laurene Tetard ; Saiful I. Khondaker
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：September 11, 2014
• 年：2014
• 卷：118
• 期：36
• 页码：21258-21263
• 全文大小：327K
• ISSN：1932-7455

文摘

By creating defects via oxygen plasma treatment, we demonstrate optical properties variation of single-layer MoS₂. We found that, with increasing plasma exposure time, the photoluminescence (PL) evolves from very high intensity to complete quenching, accompanied by gradual reduction and broadening of MoS₂ Raman modes, indicative of distortion of the MoS₂ lattice after oxygen bombardment. X-ray photoelectron spectroscopy study shows the appearance of the Mo⁶⁺ peak, suggesting the creation of MoO₃ disordered regions in the MoS₂ flake. Finally, using band structure calculations, we demonstrate that the creation of MoO₃ disordered domains upon exposure to oxygen plasma leads to a direct-to-indirect bandgap transition in single-layer MoS₂, which explains the observed PL quenching.